U.S. patent application number 17/133054 was filed with the patent office on 2022-06-23 for torch ignitors with gas assist start.
This patent application is currently assigned to Delavan Inc.. The applicant listed for this patent is Delavan Inc.. Invention is credited to Jason Ryon, Brandon Phillip Williams.
Application Number | 20220195920 17/133054 |
Document ID | / |
Family ID | |
Filed Date | 2022-06-23 |
United States Patent
Application |
20220195920 |
Kind Code |
A1 |
Ryon; Jason ; et
al. |
June 23, 2022 |
TORCH IGNITORS WITH GAS ASSIST START
Abstract
An embodiment of a torch ignitor system for combustor of a gas
turbine engine includes a torch ignitor, the torch ignitor having a
combustion chamber oriented about an axis, the combustion chamber
having axially upstream and downstream ends defining a flow
direction through the combustion chamber, along the axis. The torch
ignitor system also includes a cap defining the axially upstream
end of the combustion chamber and oriented about the axis, wherein
the cap is configured to receive a fuel injector and at least one
glow plug, a tip at a downstream end of the combustion chamber, and
a passage for pressurized oxygen containing gas passing through the
cap from an exterior of the combustion chamber and in fluid
communication with the combustion chamber. An embodiment of a
method for starting a gas turbine engine is also disclosed.
Inventors: |
Ryon; Jason; (Carlisle,
IA) ; Williams; Brandon Phillip; (Johnston,
IA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Delavan Inc. |
West Des Moines |
IA |
US |
|
|
Assignee: |
Delavan Inc.
West Des Moines
IA
|
Appl. No.: |
17/133054 |
Filed: |
December 23, 2020 |
International
Class: |
F02C 7/04 20060101
F02C007/04; F23R 3/00 20060101 F23R003/00; F23R 3/34 20060101
F23R003/34; F02C 3/00 20060101 F02C003/00 |
Claims
1. A torch ignitor system for a combustor of a gas turbine engine,
comprises: a torch ignitor comprising: a combustion chamber
oriented about an axis, the combustion chamber having axially
upstream and downstream ends defining a flow direction through the
combustion chamber, along the axis; a cap defining the axially
upstream end of the combustion chamber and oriented about the axis,
wherein the cap is configured to receive a fuel injector and at
least one glow plug; a tip at the axially downstream end of the
combustion chamber; a passage for pressurized oxygen containing gas
passing through the cap from an exterior of the combustion chamber
and in fluid communication with the combustion chamber; a fuel
injector in the cap that includes an air inlet and a separate fuel
inlet, wherein the cap includes an air passage in fluid
communication with the air inlet of the fuel injector and a liquid
fuel passage in fluid communication with the fuel inlet of the fuel
injector, and wherein the cap includes a separate gas passage
therethrough; a high pressure engine case, wherein the cap is
mounted to an opening through the high pressure engine case; a main
combustor, wherein the tip is connected to discharge combustion
products into the main combustor to ignite a fuel/air mixture in
the main combustor; a source of pressurized air external of the
high pressure engine case connected in fluid communication with an
air passage of the cap; a source of liquid fuel external of the
high pressure engine case connected in fluid communication with a
fuel injector in the cap; and a source of pressurized oxygen
containing gas external of the high pressure engine case connected
in fluid communication with the cap.
2. The torch ignitor system as recited in claim 1, wherein the
upstream end is mounted to a high pressure engine case and the tip
is mounted to the main combustor within the high pressure engine
case for fluid communication of combustion products into the main
combustor.
3. The torch ignitor system as recited in claim 1, further
comprising: a fuel injector seat defined in the cap configured to
receive the fuel injector and provide passage for injecting fuel
and gas from the external source through the fuel injector into the
combustion chamber; and at least one glow plug seat defined in the
cap configured to receive a respective glow plug of the at least
one glow plug through the cap and into the combustion chamber.
4. The torch ignitor system as recited in claim 3, wherein the
separate gas passage is in fluid communication with the fuel
injector for providing pressure-assist to the fuel injector from an
external source of pressurized oxygen containing gas.
5. The torch ignitor system as recited in claim 4, wherein the
separate gas passage of the cap is in fluid communication with the
air inlet of the fuel injector so that the gas from both the
separate gas passage of the cap and from the air passage both feed
into the inlet of the fuel injector.
6-7 .
8. The torch ignitor system as recited in claim 3, wherein the at
least one glow plug seat is a first glow plug seat in a plurality
of glow plug seats defined through the cap, wherein the glow plug
seats are circumferentially spaced apart from one another around
the axis, wherein an air passage in fluid communication with the
air inlet of the fuel injector is defined in the cap radially
inward from the glow plug seats.
9. The torch ignitor system as recited in claim 8, wherein the cap
includes a separate air passage therethrough that is at least
partially within the air passage of the cap.
10. The torch ignitor system as recited in claim 8, wherein the cap
includes a separate air passage therethrough that is lateral from
the plurality of glow plug seats relative to the axis.
11. (canceled)
12. The torch ignitor system as recited in claim 1, further
comprising a plurality of main fuel injectors mounted to the main
combustor, wherein the combustion chamber of the torch ignitor is
outside of the main combustor, and wherein none of the main fuel
injectors includes a combustion chamber outside of the main
combustor.
13. The torch ignitor system as recited in claim 1, further
comprising a control valve in line between the source of
pressurized oxygen containing gas and the cap, wherein the control
valve is configured to control supply from the source of
pressurized oxygen containing gas to the cap.
14. The torch ignitor system as recited in claim 1, wherein the
source of oxygen containing gas is a source of oxygen.
15. The torch ignitor system as recited in claim 1, wherein the
source of oxygen containing gas is source of air.
16-20.
Description
BACKGROUND
[0001] The present disclosure relates to gas turbine engines and,
more particular, to torch ignitors and methods suitable for use in
torch ignitors used in the combustor section of a gas turbine
engine.
[0002] Torch ignitors can be used in lieu of spark ignitors to
provide an ignition source for combustors located in gas turbine
engines. Torch ignitors provide a flame to the combustion chamber
of a gas turbine engine as an ignition source rather than the
electric current provided by spark ignitors. Consequently, torch
ignitors can provide a larger target for fuel injectors within the
combustor, allowing for utilization of a greater range of fuel
injector designs. Torch ignitors are intended to remain active
while the gas turbine is operating. There may be instances where a
torch ignitor can be useful for starting a gas turbine engine but
where it is not easily feasible to start off of the gas turbine's
compressor. In these instances it is advantageous to have extra aid
to starting the torch ignitor, which can then be used to start the
main combustor of the gas turbine engine.
SUMMARY
[0003] The present disclosure provides an embodiment of a torch
ignitor system for a combustor of a gas turbine engine. The system
includes a torch ignitor, the torch ignitor including a torch wall
oriented about an axis, the torch wall having axially upstream and
downstream ends defining a flow direction through the combustion
chamber, along the axis. The torch ignitor also includes a cap
defining the axially upstream end of the combustion chamber and
oriented about the axis, wherein the cap is configured to receive a
fuel injector and at least one glow plug; a tip defining the
axially downstream end of the combustion chamber, and a passage for
pressurized oxygen containing gas passing through the cap from an
exterior of the combustion chamber and in fluid communication with
the combustion chamber.
[0004] The present disclosure additionally provides for a method
that includes issuing liquid from a fuel injector into a combustion
chamber of a torch ignitor, issuing air assist from the fuel
injector into the combustion chamber, issuing a separate stream of
assist gas into the combustion chamber, igniting a fuel air mixture
within the torch wall, and reducing the separate stream of assist
gas into the combustion chamber after the fuel air mixture is
ignited.
BREIF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a cross-sectional side elevation view of an
example of a torch ignitor within the combustion section of a gas
turbine engine.
[0006] FIG. 2 is a cross-sectional side elevation view of a cap of
the torch ignitor of FIG. 1, showing a gas assist path in
accordance with at least one aspect of this disclosure.
[0007] FIG. 3 is a cross-sectional view of a cap of a torch ignitor
showing another gas assist path in accordance with at least one
aspect of this disclosure.
[0008] FIG. 4 is a cross-sectional view of a cap of a torch ignitor
showing yet a another gas assist path accordance with at least one
aspect of this disclosure.
[0009] FIG. 5 is a cross-sectional front view of a combustor
looking upstream showing the torch ignitor of FIG. 1.
[0010] FIG. 6 is a block diagram of an example of a method for
starting a turbine engine.
DETAILED DESCRIPTION
[0011] The present disclosure presents structures and methods for
starting a torch ignitor suitable for igniting the combustor of a
gas turbine engine.
[0012] The following are non-exclusive descriptions of possible
embodiments of the present disclosure. At certain times, such as an
emergency start, one time starts, or emergency altitude relights, a
torch ignitor may be used to start the gas turbine engine, however
these instances pose a challenge in starting the gas turbine engine
if relying on the gas turbine engine compressor. Thus, it is
advantageous to have additional aid in starting the torch ignitor
in order to start the gas turbine engine in such circumstances,
such as an external source of compressed oxygen containing gas. The
systems and methods disclosed herein allow for starting a torch
ignitor, and the main combustor of the gas turbine, under
suboptimal conditions.
[0013] FIG. 1 is a cross sectional view of a torch ignitor 10 for a
combustor 24 of a gas turbine engine 100. The torch ignitor 10 can
comprise a torch wall 16 (e.g. a combustion chamber for the torch
ignitor 10) oriented about an axis A, and the torch wall 16 can
have axially upstream and downstream ends 102, 104 defining a flow
direction through the torch wall 16, along the axis A. A cap 34
(also shown in FIGS. 2-4) can define the axially upstream end of
the torch wall 16 and can also be oriented about the axis A. The
cap 34 may be separable from the torch wall 16, or may be formed
integrally with the torch wall 16. In the example shown in FIG. 1,
the cap 34 can be configured to receive a fuel injector 45, at
least one glow plug 26, a tip 106 at a downstream end of the torch
wall 16, and a passage 108 for pressurized oxygen containing gas
(e.g. assist gas). In the passage 108, pressurized oxygen
containing gas can pass through the cap 34 from an exterior of the
torch wall 16 where the pressurized oxygen containing gas can be in
fluid communication with the torch wall 16. It is contemplated
however that assist gas may be issued through the both the fuel
injector 45, features within the cap section 34, and/or through the
torch wall 16 to reach the combustion chamber interior to the torch
wall 16.
[0014] In operation, air enters the high pressure engine case 18
through inlet 17 (e.g. from a main engine compressor). Torch
ignitor 10 intakes high pressure air from the inside of
high-pressure engine case 18. The high-pressure air is channeled
through cooling channels 28 to cool torch wall 16 before it is
channeled into combustion chamber contained by torch wall 16 to be
used in combustion within torch ignitor 10 (for example as shown in
the enlarged view in FIG. 2).
[0015] The upstream end 102 of the torch ignitor 10 may be mounted
to a high pressure engine case 18 (e.g. using mounting features
within high pressure casing 18) while the tip 106 may be mounted to
a main combustor 24 within the high pressure engine case 18. The
cap 34 may be mounted to upstream end 102 through aperture 132 in
high pressure case 18 by threads or other suitable means of
retention. In this way, it is possible for the main combustor 24 to
be in fluid communication with combustion products from within the
torch wall 16, where the combustion products are produced from fuel
and pressurized oxygen containing gas from sources outside the high
pressure engine case 18. In operation, the combustion products
produced within the torch wall 16 can flow into the gas turbine
combustor (e.g. main combustor 24), and eventually used to start
the turbine, as indicated by the "to turbine" arrow.
[0016] In embodiments, such as the example shown in FIG. 2, the
torch ignitor 10 can include a fuel injector seat 112 defined in
the cap 34. The fuel injector seat 112 can be configured to receive
the fuel injector 45 and to provide a passage for injecting fuel,
air, and/or assist gas from an external source 136 through the fuel
injector 45 and into the torch wall 16. It is also possible that
the torch ignitor 10 can include at least one glow plug seat 50
defined in the cap 34. The glow plug seat 50 can be comprised of
multiple components, such as a housing and sheath, however for the
sake of simplicity, the structure will be hereinafter referred to
as the glow plug seat 50. The glow plug seat 50 can be configured
to receive the glow plug 26 through the cap 34 where the glow plug
26 can extend through the cap 34 and through the torch wall 16 to
initiate ignition in fuel and air within the torch wall 16. It is
contemplated that the glow plug seat 50 can be a first glow plug
seat 50a in a plurality of glow plug seats 50a,b. As shown
throughout the FIGS., glow plug seats 50a,b are shown
circumferentially spaced apart from one another around the axis A,
such that an air passage 118 can be defined in the cap 34 radially
inward from the glow plug seats 50a,b. The examples presented in
the FIGS. and described herein provide for at least one glow plug
26 and corresponding seat 50, for example, two glow plugs 26a,b;
however it should be appreciated by those skilled in the art that
any suitable number of glow plugs 26 (and corresponding glow plug
seats 50) can be employed.
[0017] In embodiments, such as the example shown in FIG. 2, the
fuel injector 45 can include a fuel injector seat 112, an air inlet
114, and a separate fuel inlet 116. The cap 34 can include a
separate air passage 118 in fluid communication with the air inlet
114 of the fuel injector 45 and a liquid fuel passage 120 in fluid
communication with the fuel inlet 116 of the fuel injector 45. The
cap 34 can also include a separate gas passage 108, that can be in
fluid communication with the fuel injector 45 for providing
pressure-assist to the fuel injector 45 from an external source
136.
[0018] The tip 106 of the torch ignitor 10 can be connected to the
main combustor 24 to discharge combustion products from within
torch wall 16 to the main combustor 24 for ignition of a fuel/air
mixture in the main combustor 24. The external source 136 of
pressurized gas, external of the high pressure engine case 18, can
be connected in fluid communication with the air passage 118 of the
cap 34. Further, the source of liquid fuel, external of the high
pressure engine case 18, can also be connected in fluid
communication with the fuel injector 45 in the cap 34. In addition,
the external source 136 of pressurized oxygen containing gas, can
also be connected in fluid communication with the cap 34 to provide
pressure-assisting gas from the source of pressurized gas to
initiate combustion within the torch wall 16.
[0019] In embodiments, the external source 136 can be an external
source of pressurized oxygen containing gas, for example. More
particularly, the external source 136 can be a line run from an
onboard compressed air system, or from a small pressurized
compressed gas source (e.g. a replaceable and/or rechargeable
bottle) which may activated by a valve (e.g. valve 134). It is
contemplated that a rechargeable bottle may be recharged from the
main engine compressor 17 at a high pressure operation (i.e.
takeoff condition) so that it is available for the next start or
restart sequence. While not specifically described herein, it
should be appreciated by those skilled in the art that various
methods of activating the compressed gas supply to the torch
ignitor can be used, for example a solenoid to rupture an aperture
of the compressed gas tank, or a solenoid valve to open a
compartment, among other suitable methods.
[0020] Referring FIG. 2, the separate gas passage 108 of the cap 34
can be in fluid communication with the air inlet 114 of the fuel
injector 45 so that gas from both the gas passage 108 of the cap 34
and air from the air passage 118 can both feed into an inlet 124 of
the fuel injector 45. For example, compressed gas from an external
source 136 can be inserted directly into the stream of air from air
passage 118, through separate gas passage 108. The compressed
oxygen containing gas can then be used for atomizing fuel, and as
the compressed oxygen containing gas source (e.g. from the main
engine compressor 17) becomes adequate, the compressed oxygen
containing gas supply can be reduced and/or turned off via a valve
134. When gas from the compressed gas source is also used for
atomization, such as shown in FIG. 2 for example, air from the main
engine compressor 17 can then take over operation of the compressed
gas circuit once the gas turbine engine 100 is started and the main
engine compressor 17 is adequate.
[0021] Referring to FIG. 3, the separate gas passage 108 of the cap
34 can be connected to the fuel injector 45 at an assist gas port
126 of the fuel injector 45. The assist gas port 126 and separate
gas passage 108 can be a separate gas passage 124 of the fuel
injector 45 so that air from the air passage 118 of the cap 34
remains separate from gas in the separate gas passage 108 of the
cap 34 upstream of the fuel injector 45. Here, the compressed
oxygen containing gas can be injected into the fuel injector inlet
114 through a circuit (e.g. separate gas passage 108) directly into
the fuel injector 45, where the separate gas passage 108 is
separate from the compressed air used for atomization (e.g. the air
flowing through the air passage 118). As shown in both examples in
FIGS. 2-3, the separate gas passage 108 through the cap 34 can be
at least partially within the air passage 118 of the cap 34.
[0022] In further embodiments, such as the example shown in FIG. 4,
the cap 34 can also include a separate gas passage 108, where the
separate gas passage 108 through the cap 34 can be lateral from the
glow plug seats 50a,b relative to the axis A. As such, the separate
gas passage 108 can be in fluid communication with an outlet 128 in
the torch wall 16, where the outlet is downstream of the fuel
injector exit 122. For example, compressed oxygen containing gas
can be injected into the torch ignitor torch wall 16 via separate
gas passage 108. In such a configuration, the compressed oxygen
containing gas is may not be used for atomization of the fuel but
may provide sufficient compressed oxygen containing gas for
reacting with fuel within the torch wall 16.
[0023] It is possible that each torch ignitor 10 includes its own
fuel injector 45, and that the main combustor 24 includes a
plurality of main fuel injectors 145. It is also contemplated that
the system 1 can include a plurality of torch ignitors 10 spaced
between respective main fuel injectors 145 such as shown in FIG. 5.
For each torch ignitor 10, the torch wall 16 can be outside of the
main combustor 24, while none of the main fuel injectors 145
includes a combustion chamber outside of the main combustor 24.
[0024] In embodiments, the torch ignitor 10 can include control
valve 134 in line between the source 136 of pressurized oxygen
containing gas and the cap 34 for controlling supply from the
source 136 of pressurized oxygen containing gas to the cap 34. The
source 136 of oxygen containing gas can be any of a source of
oxygen or air, for example, roughly 21% oxygen, 79% nitrogen for an
air source, or 100% oxygen for an oxygen source, however as
appreciated by those skilled in the art, any suitable oxygen
containing gas or combination thereof can be used.
[0025] FIG. 6 shows a block diagram of a method 200 for starting a
gas turbine engine 100, using a torch ignitor system as described
above. At box 202, the method 200 can include issuing liquid (e.g.
liquid fuel from the liquid fuel passage 116) from a fuel injector
45 within torch wall 16 of a torch ignitor 10. Next, at box 204,
the method 200 can include issuing air (e.g. air from the air inlet
passage 118) from the fuel injector 45 into the torch wall 16. At
box 206, the method 200 can include issuing a separate stream of
assist gas (e.g. assist gas from separate gas passage 108) into the
torch wall 16. The method 200 can include, as shown at box 208,
igniting a fuel air mixture within the torch wall 16, and at box
202, using flame issued from the torch wall 16 to ignite a fuel/air
mixture in a combustor 24 of a gas turbine engine 100. The method
200 can include issuing the ignited combustion products from the
combustion chamber into a main combustor to ignite a fuel/air
mixture in a main combustor of a gas turbine engine, at box 210. At
box 212, using flame issued from the torch wall 16 can also include
relighting the gas turbine engine after in-flight flame out, for
example an emergency relight at altitude. At box 214, the method
200 can include reducing the separate stream of assist gas into the
torch wall 16 after the fuel air mixture is ignited. It is
contemplated that reducing the separate stream of assist gas (e.g.
box 214) can includes completely deactivating the separate stream
of assist gas, as shown at box 216, when a supply of assist gas is
no longer needed. The compressed oxygen containing gas is only
required to start the reaction, and can therefore be stopped once
the reaction is sustained.
Discussion of Possible Embodiments
[0026] The following are non-exclusive descriptions of possible
embodiments of the present disclosure.
[0027] An embodiment of a torch ignitor system for combustor of a
gas turbine engine includes a torch ignitor, the torch ignitor
having a combustion chamber oriented about an axis, the combustion
chamber having axially upstream and downstream ends defining a flow
direction through the combustion chamber, along the axis. The torch
ignitor system also includes a cap defining the axially upstream
end of the combustion chamber and oriented about the axis, wherein
the cap is configured to receive a fuel injector and at least one
glow plug, a tip at a downstream end of the combustion chamber, and
a passage for pressurized oxygen containing gas passing through the
cap from an exterior of the combustion chamber and in fluid
communication with the combustion chamber.
[0028] The system of the preceding paragraph can optionally
include, additionally and/or alternatively, any one or more of the
following features, configurations and/or additional
components:
[0029] A torch ignitor system for combustor of a gas turbine engine
according to an exemplary embodiment of this disclosure, among
other possible things, includes the upstream end mounted to a high
pressure engine case and the tip is mounted to a main combustor
within the high pressure case for fluid communication combustion
products into the combustor.
[0030] A further embodiment of the foregoing system can further
comprise, a fuel injector seat defined in the cap configured to
receive the fuel injector and provide passage for injecting fuel
and gas from an external source through the fuel injector into the
combustion chamber, and at least one glow plug seat defined in the
cap configured to receive a respective glow plug of the at least
one glow plug through the cap and into the combustion chamber for
initiating ignition in fuel and air in the combustion chamber.
[0031] A further embodiment of any of the foregoing systems,
wherein the fuel injector includes an air inlet and a separate fuel
inlet, wherein the cap includes an air passage in fluid
communication with the air inlet of the fuel injector and a liquid
fuel passage in fluid communication with the fuel inlet of the fuel
injector, and wherein the cap includes a separate gas passage
therethrough, wherein the separate gas passage is in fluid
communication with the fuel injector for providing pressure-assist
to the fuel nozzle from an external source of pressurized oxygen
containing gas.
[0032] A further embodiment of any of the foregoing systems,
wherein the separate gas passage of the cap is in fluid
communication with the air inlet of the fuel injector so that gas
from both the gas passage of the cap and from the air passage both
feed into the inlet of the fuel injector.
[0033] A further embodiment of any of the foregoing systems,
wherein the separate gas passage of the cap is connected to the
fuel injector at an assist gas port of the fuel injector that is
separate from the inlet of the fuel injector keeping air from the
air passage of the cap separate from gas in the separate gas
passage of the air cap upstream of the fuel injector.
[0034] A further embodiment of any of the foregoing systems,
wherein the fuel injector includes an air inlet and a separate fuel
inlet, wherein the cap includes an air passage in fluid
communication with the air inlet of the fuel injector and a liquid
fuel passage in fluid communication with the fuel inlet of the fuel
injector, and wherein the cap includes a separate gas passage
therethrough with an outlet in the combustion chamber downstream of
a fuel nozzle.
[0035] A further embodiment of any of the foregoing systems,
wherein the at least one glow plug seat is a first glow plug seat
in a plurality of glow plug seats defined through the cap, wherein
the glow plug seats are circumferentially spaced apart from one
another around the axis, wherein an air passage in fluid
communication with the air inlet of the fuel injector is defined in
the cap radially inward from the glow plug seats.
[0036] A further embodiment of any of the foregoing systems,
wherein the cap includes a separate gas passage therethrough that
is at least partially within the air passage of the cap.
[0037] A further embodiment of any of the foregoing systems,
wherein the cap includes a separate gas passage therethrough that
is lateral from the glow plug seats relative to the axis.
[0038] An embodiment of a torch ignitor system for combustor of a
gas turbine engine can further comprise a high pressure engine
case, wherein the cap is mounted to an opening through the high
pressure engine case, a main combustor, wherein the tip is
connected to discharge combustion products into the main combustor,
a source of pressurized air external of the high pressure engine
case connected in fluid communication with an air passage of the
air cap, a source of liquid fuel external of the high pressure case
connected in fluid communication with a fuel injector in the cap,
and a source of pressurized oxygen containing gas external of the
high pressure engine case connected in fluid communication with the
cap.
[0039] A further embodiment of any of the foregoing systems can
further comprise a plurality of main fuel injectors mounted to the
main combustor, wherein the torch combustion chamber is outside of
the main combustor, and wherein none of the main fuel injectors
includes a combustion chamber outside of the main combustor.
[0040] A further embodiment of any of the foregoing systems can
further comprise a control valve in line between the source of
pressurized oxygen containing gas and the cap wherein the control
valve is configured to control supply from the source of
pressurized oxygen containing gas to the cap.
[0041] A further embodiment of any of the foregoing systems,
wherein the source of oxygen containing gas is a source of
oxygen.
[0042] A further embodiment of any of the foregoing systems,
wherein the source of oxygen containing gas is source of air.
[0043] An embodiment of a method includes issuing liquid from a
fuel injector into a combustion chamber of a torch ignitor, issuing
air from the fuel injector into the combustion chamber, issuing a
separate stream of assist gas into the combustion chamber, igniting
a fuel air mixture within the combustion chamber, and reducing the
separate stream of assist gas into the combustion chamber after the
fuel air mixture is ignited.
[0044] The method of the preceding paragraph can optionally include
using flame issued from the combustion chamber to ignite a fuel/air
mixture in a main combustor of a gas turbine engine.
[0045] A further embodiment of any of the foregoing methods,
wherein using flame issued from the combustion chamber includes
relighting the gas turbine engine after in-flight flame out.
[0046] A further embodiment of any of the foregoing methods,
wherein reducing the separate stream of assist gas includes
completely deactivating the separate stream of assist gas.
[0047] A further embodiment of any of the foregoing methods,
wherein the assist gas includes at least one of air and/or
oxygen.
[0048] While the invention has been described with reference to an
exemplary embodiment(s), it will be understood by those skilled in
the art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment(s) disclosed, but that the invention will
include all embodiments falling within the scope of the appended
claims.
* * * * *